I email every single customer within 24-48 hours of purchase and try to engage in similar conversation. I've learned quite a bit about our audience, our product

I email every single customer within 24-48 hours of purchase and try to engage in similar conversation. I've learned quite a bit about our audience, our product, and our product expectations as a result of that. I'm not sure adding features on the fly is something I'm into, but I do take all feature requests to heart. Was it Steve Blank that said something about no product surviving first encounter with a customer?